Radio frequency (RF) power amplifiers are often used in portable battery operated wireless devices, such as cellular telephones. Extending the battery life is a key concern for users and manufacturers of these battery operated wireless devices. One of the key factors in determining the battery life of the battery operated wireless device is the power consumption of the RF power amplifiers. The RF power amplifiers are designed to operate into an optimal load impedance and are typically coupled to an antenna of the battery operated wireless device.
However, under an antenna mismatch condition, such as for example, when the antenna of the battery operated wireless device approaches objects (e.g. metal structures, human contact, or the like), the load impedance of the RF power amplifier changes and the RF power amplifier draws excess current. In some cases, the current can exceed more than two times the current drawn under an optimal load impedance. When the RF power amplifier draws excess current, the battery life of the battery operated wireless device is reduced. In addition, the adjacent channel power ratio (ACPR) and error vector magnitude (EVM) linearity and distortion limits are often exceeded when the RF power amplifier draws excess current.